Circuit-closer



(No Model.)

G. E. ALLEN.

GIRGUI'T CLOSER. v No. 517,401. Patented Mar. 27, 1894.

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wimm y%%%- electric circuit closing devices, and it has for its ob ectthe provision of a simple, compact 'UNITED STATES PATENT OFFICE.

CHARLES ELMER ALLEN, Oh SALEM, MASSACHUSETTS.

CIRCUIT-CLOSER.

SPECIFICATION forming part of Letters Patent No. 517,401, dated March27, 1894.

Application filed December 29, 1893. Serial No. 495,097. (No model.)

To all whom it may concern.-

Be it known that I, CHARLES ELMER ALLEN, a citizen of the United States,residing at Salem, in the county of Essex and State of Massachusetts,have invented certain new and useful Improvements in Circuit-Closers;and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawing, and to the letters of reference markedthereon, which form a part of this specificaion.

This invention relates to improvements in and reliable circuit closingdevice; and the lnvention consists essentially of a key or push buttonand a mercury contact therefor, whereby a continuous and uninterruptedmetallic circuit can be obtained, and it consists of such constructionas to be operated by a very slight touch of the finger, yetalwaysinsures a perfect metallic path for the current, uninterrupted bydirt, dust or other defects common to electric keys, such as loosejoints and sliding contacts.

The invention further consists in the construction and novel arrangementof parts hereinafter described, illustrated in the drawing and moreparticularly pointed out in the claims hereunto appended. I

In the drawing the figure is a vertical section of the device showingthe relative positron and arrangement of the several parts. A is areceptacle or casing made of cast iron, orany other suitable metal, andis deslgned to hold a small quantity of mercury for a purposehereinafter described.

b is a piece of hard rubber or other insulating material, and has at oneend thereof a flange 1) extending around it, as shown. This hard rubberpiece b fits tightly in the receptacle A and is supported therein by theflange b which rests upon the sides or walls a, a, of the receptacle A,as shown. The said rubber piece I) has in it centrally thereof acylindrical chamber or recess B, and an opening B extending from thesaid recess through the block, thus making a passage through the saidpiece I), as shown. Into this chamber or recess is placed a key or pushbutton, the stem of which extends down below the under side of the hardrubber piece into thereceptacle A. When this stem is in its normalposition it rests just above the surface of the mercury in thereceptacle A, and only enters the mercury when the button to which it issecured is depressed.

The construction of the key is as follows: K is a suitable head made ofany non-conducting material, and is provided with a suitable flange orcollar is for a purpose hereinafter described. In the under side orbottom of this button is secured a stem 7', preferably of Bessemer steelor copper wire. Surrounding this stem 0" is a spiral spring 8 the upperend of which is passed through an opening in the button and stem and istightly bound or secured therein by means of a pin 1' in the hole Z. Thelower end of the spring is secured to a metallic collar t by means of abinding screw w, or otherwise. This collar fits tightly in the open endof the chamber or recess B, and is provided with a central opening ofsuch size as to permit a free reciprocation of the stem 1' therethrough,and yet be sufficiently tight to prevent the escape of the mercury intothe chamber B. On the under side of this collar is a binding screw '0for securing one end of a wire or other conductor 2 which passes upthrough a proper opening or channel in the hard rubber and is connectedto a binding post 0 on the outer surface thereof, as is apparent.

c is a binding post that passes through the flange 1) down into the wallof the receptacle A, as shown.

This key or push button is fitted into the chamber B, the head k fittingin the opening B and is prevented being pushed out by the flange k whichlimits its upward movement. The collar 15 is fitted into the end of thechamber B, as described.

M isa suitable quantity of mercury in the bottom of the receptacle A.

The operation of this device is as follows:

A slight pressure on the head of the key causes the stem to enter themercury in the bottom of the receptacle, thus establishing a metalliccircuit without joints or sliding contacts. In this device the metalliccircuit would be through the binding post 0, the

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walls or sides a, a, of the receptacle A, mercury M, stem r, pin Z,spring 3, collar 15, wire 2 to the binding post 0'.

Having thus described my invention, what I claim is- 1. The combinationof an electric key or push button consisting of a head, a stem securedtherein, a spiral spring surrounding said stem and secured in an openingin the upper end thereof, a collar surrounding said stem and to whichthe lower end of said spring is secured, whereby the stem, spring andcollar become part of one and the same unbroken and continuous metalliccircuit, and a contact co-operating with the lower end of the stem asset forth.

2. A circuit closer of the character described consisting of aninsulating support or block,

a chamber therein, a key in said chamber consisting of a head, a stemsecured therein, a spiral spring surrounding said stem and secured in anopening in said head and the up per part of the stem, a collarsurrounding

